The impact of offshoring on average labor productivity is investigated on a panel of 17 manufacturing sectors between 1989-2006. As proxies for offshoring, we use imports and import penetration, defined as the ratio of imports to output. We disaggregate the universe of exporters into low wage countries, NAFTA and the rest of the world. Controlling for production inputs, significant increases in productivity are explained by the growth of imports weighted by import penetration. The exception are imports from NAFTA which have a negative impact on productivity.